Related Experiment Videos
Biased immunoglobulin variable region gene expression by Ly-1 B cells due to clonal selection
C A Pennell1, T J Mercolino, T A Grdina
1Department of Microbiology and Immunology, University of North Carolina, Chapel Hill 27599.
European Journal of Immunology
|July 1, 1989
Summary
Autoantibodies targeting phosphatidyl choline (PtC) are primarily produced by Ly-1 B cells in mice. Antigen selection, not just gene rearrangement, influences the B cell repertoire, suggesting a germ line-encoded function.
Area of Science:
- Immunology
- Molecular Biology
- Autoimmunity
Background:
- Autoantibodies recognizing phosphatidyl choline (PtC) are found on bromelain-treated mouse erythrocytes.
- These PtC-specific antibodies are predominantly produced by CD5+ Ly-1 B cells, not conventional CD5- B cells.
Purpose of the Study:
- To investigate the mechanisms driving the high frequency of PtC-specific B cells.
- To determine the role of antigen selection versus V gene rearrangement in shaping the Ly-1 B cell repertoire.
Main Methods:
- Analysis of heavy and kappa chain variable (V) region gene combinations in PtC-specific Ly-1 B cells.
- Sequencing of DH genes and V kappa-J kappa junctions.
- Comparison of findings with preferential V gene rearrangement models.
Main Results:
- PtC-specific Ly-1 B cells predominantly express two specific heavy and kappa chain V region gene combinations.
- Conserved DH gene sequences and unusual V kappa-J kappa splice sites were observed.
- The delayed appearance and high frequency of PtC-specific cells suggest antigen selection is a key factor.
Conclusions:
- Antigen selection significantly influences the expressed V gene repertoire of Ly-1 B cells.
- The lack of mutations in V region genes suggests no affinity maturation selection occurred.
- Findings support a germ line-encoded function for the immunoglobulin products of these specific V gene combinations.